Final-state rescattering effects on Bd→ππ decays and CP violation

The significance of final-state interactions in Bd→ππ decays is phenomenologically demonstrated by taking elastic ππ⇌ππ and inelastic ππ⇌DD̄ rescattering effects into consideration. We find that the present experimental data on B0d→π+π− can well be understood in this approach without fine-tuning of the input parameters, and large CP-violating asymmetries are expected to manifest themselves in such charmless rare processes.